[PATCH V5 1/2] firmware: arm_scmi: Add QCOM Generic Vendor Protocol documentation

Cristian Marussi cristian.marussi at arm.com
Wed Dec 4 03:48:26 PST 2024


On Fri, Nov 15, 2024 at 06:45:14AM +0530, Sibi Sankar wrote:
> Add QCOM System Control Management Interface (SCMI) Generic Vendor
> Extensions Protocol documentation.
> 
> Signed-off-by: Sibi Sankar <quic_sibis at quicinc.com>
> ---
> 
> v4:
> * Update the protol attributes doc with more information. [Cristian]
> 
>  .../arm_scmi/vendors/qcom/qcom_generic.rst    | 211 ++++++++++++++++++
>  1 file changed, 211 insertions(+)
>  create mode 100644 drivers/firmware/arm_scmi/vendors/qcom/qcom_generic.rst
> 
> diff --git a/drivers/firmware/arm_scmi/vendors/qcom/qcom_generic.rst b/drivers/firmware/arm_scmi/vendors/qcom/qcom_generic.rst
> new file mode 100644
> index 000000000000..141bc932e30f
> --- /dev/null
> +++ b/drivers/firmware/arm_scmi/vendors/qcom/qcom_generic.rst
> @@ -0,0 +1,211 @@
> +.. SPDX-License-Identifier: GPL-2.0
> +.. include:: <isonum.txt>
> +
> +===============================================================================
> +QCOM System Control and Management Interface(SCMI) Vendor Protocols Extension
> +===============================================================================
> +
> +:Copyright: |copy| 2024, Qualcomm Innovation Center, Inc. All rights reserved.
> +
> +:Author: Sibi Sankar <quic_sibis at quicinc.com>
> +
> +SCMI_GENERIC: System Control and Management Interface QCOM Generic Vendor Protocol
> +==================================================================================
> +
> +This protocol is intended as a generic way of exposing a number of Qualcomm
> +SoC specific features through a mixture of pre-determined algorithm string and
> +param_id pairs hosted on the SCMI controller. It implements an interface compliant
> +with the Arm SCMI Specification with additional vendor specific commands as
> +detailed below.
> +
> +Commands:
> +_________
> +
> +PROTOCOL_VERSION
> +~~~~~~~~~~~~~~~~
> +
> +message_id: 0x0
> +protocol_id: 0x80
> +
> ++---------------+--------------------------------------------------------------+
> +|Return values                                                                 |
> ++---------------+--------------------------------------------------------------+
> +|Name           |Description                                                   |
> ++---------------+--------------------------------------------------------------+
> +|int32 status   |See ARM SCMI Specification for status code definitions.       |
> ++---------------+--------------------------------------------------------------+
> +|uint32 version |For this revision of the specification, this value must be    |
> +|               |0x10000.                                                      |
> ++---------------+--------------------------------------------------------------+
> +
> +PROTOCOL_ATTRIBUTES
> +~~~~~~~~~~~~~~~~~~~
> +
> +message_id: 0x1
> +protocol_id: 0x80
> +
> ++---------------+--------------------------------------------------------------+
> +|Return values                                                                 |
> ++------------------+-----------------------------------------------------------+
> +|Name              |Description                                                |
> ++------------------+-----------------------------------------------------------+
> +|int32 status      |See ARM SCMI Specification for status code definitions.    |
> ++------------------+-----------------------------------------------------------+
> +|uint32 attributes |Bits[31:16] Reserved, must be to 0.                        |
> +|                  |Bits[15:8] Number of agents in the system                  |
> +|                  |Bits[7:0] Number of vendor protocols in the system         |
> ++------------------+-----------------------------------------------------------+

Thanks of clarifing this....may I ask why number of agents is reported
here too given that it is already exposed by Base protocol ?

Not really arguing about this so much, but you will end up having to maintain this
on 2 different protocols fw side...or are they not 'agents' in the SCMI meaning ?

Anyway, I'm fine with it, even though you dont seem to use this
anywhere.

> +
> +PROTOCOL_MESSAGE_ATTRIBUTES
> +~~~~~~~~~~~~~~~~~~~~~~~~~~~
> +
> +message_id: 0x2
> +protocol_id: 0x80
> +
> ++---------------+--------------------------------------------------------------+
> +|Return values                                                                 |
> ++------------------+-----------------------------------------------------------+
> +|Name              |Description                                                |
> ++------------------+-----------------------------------------------------------+
> +|int32 status      |See ARM SCMI Specification for status code definitions.    |
> ++------------------+-----------------------------------------------------------+
> +|uint32 attributes |For all message id's the parameter has a value of 0.       |
> ++------------------+-----------------------------------------------------------+
> +
> +QCOM_SCMI_SET_PARAM
> +~~~~~~~~~~~~~~~~~~~
> +
> +message_id: 0x10
> +protocol_id: 0x80
> +
> ++------------------+-----------------------------------------------------------+
> +|Parameters                                                                    |
> ++------------------+-----------------------------------------------------------+
> +|Name              |Description                                                |
> ++------------------+-----------------------------------------------------------+
> +|uint32 ext_id     |Reserved, must be zero.                                    |
> ++------------------+-----------------------------------------------------------+
> +|uint32 algo_low   |Lower 32-bit value of the algorithm string.                |
> ++------------------+-----------------------------------------------------------+
> +|uint32 algo_high  |Upper 32-bit value of the algorithm string.                |
> ++------------------+-----------------------------------------------------------+
> +|uint32 param_id   |Serves as the token message id for the algorithm string    |
> +|                  |and is used to set various parameters supported by it.     |
> ++------------------+-----------------------------------------------------------+
> +|uint32 buf[]      |Serves as the payload for the specified param_id and       |
> +|                  |algorithm string pair.                                     |
> ++------------------+-----------------------------------------------------------+
> +|Return values                                                                 |
> ++------------------+-----------------------------------------------------------+
> +|Name              |Description                                                |
> ++------------------+-----------------------------------------------------------+
> +|int32 status      |SUCCESS: if the param_id and buf[] is parsed successfully  |
> +|                  |by the chosen algorithm string.                            |
> +|                  |NOT_SUPPORTED: if the algorithm string does not have any   |
> +|                  |matches.                                                   |
> +|                  |INVALID_PARAMETERS: if the param_id and the buf[] passed   |
> +|                  |is rejected by the algorithm string.                       |
> ++------------------+-----------------------------------------------------------+
> +
> +QCOM_SCMI_GET_PARAM
> +~~~~~~~~~~~~~~~~~~~
> +
> +message_id: 0x11
> +protocol_id: 0x80
> +
> ++------------------+-----------------------------------------------------------+
> +|Parameters                                                                    |
> ++------------------+-----------------------------------------------------------+
> +|Name              |Description                                                |
> ++------------------+-----------------------------------------------------------+
> +|uint32 ext_id     |Reserved, must be zero.                                    |
> ++------------------+-----------------------------------------------------------+
> +|uint32 algo_low   |Lower 32-bit value of the algorithm string.                |
> ++------------------+-----------------------------------------------------------+
> +|uint32 algo_high  |Upper 32-bit value of the algorithm string.                |
> ++------------------+-----------------------------------------------------------+
> +|uint32 param_id   |Serves as the token message id for the algorithm string.   |
> ++------------------+-----------------------------------------------------------+
> +|uint32 buf[]      |Serves as the payload and store of value for the specified |
> +|                  |param_id and algorithm string pair.                        |
> ++------------------+-----------------------------------------------------------+
> +|Return values                                                                 |
> ++------------------+-----------------------------------------------------------+
> +|Name              |Description                                                |
> ++------------------+-----------------------------------------------------------+
> +|int32 status      |SUCCESS: if the param_id and buf[] is parsed successfully  |
> +|                  |by the chosen algorithm string and the result is copied    |
> +|                  |into buf[].                                                |
> +|                  |NOT_SUPPORTED: if the algorithm string does not have any   |
> +|                  |matches.                                                   |
> +|                  |INVALID_PARAMETERS: if the param_id and the buf[] passed   |
> +|                  |is rejected by the algorithm string.                       |
> ++------------------+-----------------------------------------------------------+

..missed this last time...so you should add here also a field describing
the reply buf right ? (as it happenns really in your code) something
like:

 ++------------------+-----------------------------------------------------------+
 +|uint32 buf[]      |Holds the payload of the result of the query.	 	 |
 +|                  |					                         |
 ++------------------+-----------------------------------------------------------+

Thanks,
Cristian



More information about the linux-arm-kernel mailing list